There’re 4 ways to silence the ringer before answering a call.
Method 1: Press the Volume Down/Up or Power button on the side of your device.
Method 2:Enable the Gesture function by going to the “Phone” app and pressing the menu key in the top right corner of the screen. Then go to “Settings” -> “Accessibility” and activate “Turn over to mute”. You can then mute incoming calls by turning the phone over when a call is being received.
Method 3: Go to menu -> “Settings” -> “Sound”-> activate “Silent mode”.
Method 4: Drag the Status Bar down with your finger and then touch the “Notification” icon to change to “Vibrate” or “Mute”.
Note: Press the “power” key and “volume up” key at the same time to switch to vibration mode quickly.